This invention relates to the handling of lumber on a conveyer, and more particularly to a method and apparatus for center positioning the lumber intermediate its end on the conveyor.
After lumber has been sawed to its desired size, it must be transported, sorted for length, width, grade, lot, etc., and stacked for drying. Conveyors comprising a plurality of endless chains in parallel lines are used for this purpose. Since these lines must transport the lumber through the entire process, they are long, sometimes extending up to 300 feet or more in over-all length.
The number of side by side conveyor lines required depends upon the lengths of the lumber being transported. In the prior art handling systems the lumber is disposed randomly laterally on these conveyor lines, requiring additional lines for supporting the lumber. For example, a system handling lumber ranging from 8 feet to 24 feet in length requires a minimum of 5 such lines to carry the lumber. Due to this requirement of multiple lines the initial cost and maintenance of the prior art lumber handling systems are high.
In addition when the lumber is disposed randomly on the lines of the prior art handling systems, it will be deposited onto the handling equipment, such as a sorter, in a disorderly manner. As a result, the lumber is unstable and may cause asymmetrical loading of the sorter. This particularly is a problem in cart sorters having spring loaded positionable floors, as the floors may be displaced unevenly and jam. In addition with a bin type sorter a single load cable may be utilized in place of the common double cable arrangement, lowering the initial cost of the sorter.